Compliant snoring treatment implant

ABSTRACT

A method and apparatus for treating snoring include selecting an implant formed of a bio-compatible material having a longitudinal length between a proximal end and a distal end. The material is compliant in response to tensile forces along the length. The material is sized to be inserted into the soft palate with the longitudinal length extending aligned with an anterior-posterior axis of the palate and with the thickness contained within a thickness of the soft palate.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] The present application is a continuation-in-part of U.S. patentapplication Ser. No. 09/602,141 filed Jun. 23, 2000 which is acontinuation-in-part of U.S. patent application Ser. Nos. 09/513,432 and09/513,039 filed Feb. 25, 2000, which are continuations-in-part of U.S.patent application Ser. No. 09/434,653 filed on Nov. 5, 1999 which is acontinuation-in-part of U.S. patent application Ser. No. 09/398,991filed Sep. 17, 1999, and with priority being claimed to all of thefore-going.

BACKGROUND

[0002] 1. Field of the Invention

[0003] This invention is directed to methods and apparatuses fortreating snoring. More particularly, this invention is directed such amethod and apparatus incorporating a compliant implant.

[0004] 2. Description of the Prior Art

[0005] Snoring has received increased scientific and academic attention.One publication estimates that up to 20% of the adult population snoreshabitually. Huang, et al., “Biomechanics of Snoring”, Endeavour, p.96-100, Vol. 19, No. 3 (1995). Snoring can be a serious cause of maritaldiscord. In addition, snoring can present a serious health risk to thesnorer. In 10% of habitual snorers, collapse of the airway during sleepcan lead to obstructive sleep apnea syndrome. Id.

[0006] Notwithstanding numerous efforts to address snoring, effectivetreatment of snoring has been elusive. Such treatment may include mouthguards or other appliances worn by the snorer during sleep. However,patients find such appliances uncomfortable and frequently discontinueuse (presumably adding to marital stress).

[0007] Electrical stimulation of the soft palate has been suggested totreat snoring and obstructive sleep apnea. See, e.g., Schwartz, et al.,“Effects of electrical stimulation to the soft palate on snoring andobstructive sleep apnea”, J. Prosthetic Dentistry, pp. 273-281 (1996).Devices to apply such stimulation are described in U.S. Pat. Nos.5,284,161 and 5,792,067. Such devices are appliances requiring patientadherence to a regimen of use as well as subjecting the patient todiscomfort during sleep. Electrical stimulation to treat sleep apnea isdiscussed in Wiltfang, et al., “First results on daytime submandibularelectrostimulation of suprahyoidal muscles to prevent night-timehypopharyngeal collapse in obstructive sleep apnea syndrome”,International Journal of Oral & Maxillofacial Surgery, pp. 21-25 (1999).

[0008] Surgical treatments have been employed. One such treatment isuvulopalatopharyngoplasty. In this procedure, so-called laser ablationis used to remove about 2 cm of the trailing edge of the soft palatethereby reducing the soft palate's ability to flutter between the tongueand the pharyngeal wall of the throat. The procedure is frequentlyeffective to abate snoring but is painful and frequently results inundesirable side effects. Namely, removal of the soft palate trailingedge comprises the soft palate's ability to seal off nasal passagesduring swallowing and speech. In an estimated 25% ofuvulopalatopharyngoplasty patients, fluid escapes from the mouth intothe nose while drinking. Huang, et al., supra at 99.Uvulopalatopharyngoplasty (UPPP) is also described in Harries, et al.,“The Surgical treatment of snoring”, Journal of Laryngology and Otology,pp. 1105-1106 (1996) which describes removal of up to 1.5 cm of the softpalate. Assessment of snoring treatment is discussed in Cole, et al.,“Snoring: A review and a Reassessment”, Journal of Otolaryngology, pp.303-306 (1995).

[0009] Huang, et al., supra, describe the soft palate and palatalsnoring as an oscillating system which responds to airflow over the softpalate. Resulting flutter of the soft palate (rapidly opening andclosing air passages) is a dynamic response generating sounds associatedwith snoring. Huang, et al., propose an alternative touvulopalatopharyngoplasty. The proposal includes using a surgical laserto create scar tissue on the surface of the soft palate. The scar is toreduce flexibility of the soft palate to reduce palatal flutter. Huang,et al., report initial results of complete or near-complete reduction insnoring and reduced side effects.

[0010] Surgical procedures such as uvulopalatopharyngoplasty and thoseproposed by Huang, et al., continue to have problems. The area ofsurgical treatment (i.e., removal of palatal tissue or scarring ofpalatal tissue) may be more than is necessary to treat the patient'scondition. Surgical lasers are expensive. The proposed procedures arepainful with drawn out and uncomfortable healing periods. The procedureshave complications and side effects and variable efficacy (e.g., Huang,et al., report promising results in 75% of patients suggesting a fullquarter of patients are not effectively treated after painful surgery).The procedures may involve lasting discomfort. For example, scar tissueon the soft palate may present a continuing irritant to the patient.Importantly, the procedures are not reversible in the event they happento induce adverse side effects not justified by the benefits of thesurgery.

SUMMARY OF THE INVENTION

[0011] According to a preferred embodiment of the present invention, amethod and apparatus are disclosed for treating snoring of a patientattributable at least in part to motion of a soft palate of the patient.The method and apparatus include selecting an implant formed of abio-compatible material having a longitudinal length between a proximalend and a distal end. The material is compliant in response to tensileforces along the length. The material is sized to be inserted into thesoft palate with the longitudinal length extending aligned with ananterior-posterior axis of the palate and with the thickness containedwithin a thickness of the soft palate.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIG. 1 is a side sectional view of a portion of a human headshowing a soft palate in a relaxed state and in relation in adjacentanatomical features;

[0013]FIG. 2 is a portion of the view of FIG. 1 showing the soft palatein a flexed state;

[0014]FIG. 3 is a front view of an interior of the mouth shown in FIG. 1and showing an area to be ablated according to a first prior artsurgical procedure;

[0015]FIG. 4 is the view of FIG. 3 and showing an area to be scarredaccording to a second prior art surgical procedure;

[0016]FIG. 5 is a schematic representation of a spring-mass system modelof the soft palate;

[0017]FIG. 6 is the view of FIG. 1 with the soft palate containing animplant according to a first embodiment of the present invention;

[0018]FIG. 7 is the view of FIG. 3 showing the embodiment of FIG. 6;

[0019]FIG. 8 is a cross-sectional view of the implant of FIG. 6;

[0020]FIG. 9 is a first modification of the implant of FIG. 8 having atissue in-growth layer;

[0021]FIG. 10 is a second modification of the implant of FIG. 8 having asmooth outer layer;

[0022]FIG. 11 is the view of FIG. 6 with the soft palate containing animplant according to a second embodiment of the present invention;

[0023]FIG. 12 is the view of FIG. 7 showing the embodiment of FIG. 11;

[0024]FIG. 13 is a perspective view of the implant of FIG. 11;

[0025]FIG. 14 is a cross-sectional view of the implant of FIG. 13;

[0026]FIG. 15 is a view of the implant of FIG. 14 with the implantpre-formed to assume the shape of a soft palate in a relaxed state;

[0027]FIG. 16 is the view of FIG. 14 with the implant constructed tohave greater flexion in a downward direction;

[0028]FIG. 17 is an exploded perspective view of first modification ofthe implant of FIG. 13;

[0029]FIG. 18 is a perspective view of a modification of a housing ofthe embodiment of FIG. 17;

[0030]FIG. 19 is a side section view of a second modification of theimplant of FIG. 13;

[0031]FIG. 20 is a cross-sectional view of an implant that is anotherembodiment of the present invention, the implant is shown in a flattenedorientation;

[0032]FIG. 21 is a cross-sectional view of the implant of FIG. 20 in anexpanded orientation;

[0033]FIG. 22 shows the implant of FIG. 20 in the flattened orientationand implanted in the soft palate;

[0034]FIG. 23 shows the implant in FIG. 21 in the expanded orientationand implanted in the soft palate;

[0035]FIG. 24 is a top plan view, shown partially broken away, of astill further embodiment of the present invention;

[0036]FIG. 25 is a view taken along line 25-25 in FIG. 24;

[0037]FIG. 26 is a side sectional view of the implant of FIG. 24collapsed and placed within a delivery tool;

[0038]FIG. 27 is the view of FIG. 26 with the implant in the process ofbeing ejected from the delivery tool;

[0039]FIG. 28 is a view taken along line 28-28 in FIG. 26;

[0040]FIG. 29 is a side sectional view of the soft palate showing apalatal muscle in the soft palate;

[0041]FIG. 30 is the view of FIG. 29 showing the delivery tool of FIG.26 being advanced through an incision into the soft palate;

[0042]FIG. 31 is the view of FIG. 30 following delivery of the implantand removal of the delivery tool; and

[0043]FIG. 32 is a view taken along line 32-32 in FIG. 31.

[0044]FIG. 33 is a perspective view of an implant according to a stillfurther embodiment of the present invention showing only abio-resorbable, first component;

[0045]FIG. 34 is a perspective view of the implant of FIG. 33 showingboth a first component and a second component;

[0046]FIG. 35 is a perspective of the implant of FIG. 33 showing onlythe second component following bio-resorption of the first component;

[0047]FIG. 36 is a graph showing decrease of palatal stiffeningattributable to the first component and increase of palatal stiffeningattributable to the first component;

[0048]FIG. 37 is a perspective view of an implant for use in thedelivery system of FIGS. 38-39;

[0049]FIG. 38 is a side-sectional view of a delivery system for placingan implant in the soft palate;

[0050]FIG. 39 is the view of FIG. 38 following delivery of the implantfrom the delivery system;

[0051]FIG. 40 is a perspective view of a braided implant;

[0052]FIG. 41 is an end view of the implant of FIG. 40;

[0053]FIG. 42 is a side sectional view of an implant with an anchor;

[0054]FIG. 43 shows an implant in a perforated needle tip;

[0055]FIG. 44 is a cross-sectional view of the implant and needle tip ofFIG. 43;

[0056]FIG. 45 is a view of a compliant implant in a soft palate;

[0057]FIG. 46 is a side view of an embodiment of an implant whichcontracts in a longitudinal dimension and shown in an extended state;

[0058]FIG. 47 is the view of FIG. 46 with the implant shown in acontracted state;

[0059]FIG. 48 is a perspective view of an embodiment of an implant whichcontracts in multiple dimensions and shown in an extended state;

[0060]FIG. 49 is a view of the implant of FIG. 48 shown contracted.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0061] For ease of understanding the present invention, the dynamics ofsnoring are explained with reference to FIGS. 1-4. The hard palate HPoverlies the tongue T and forms the roof of the mouth M. The hard palateHP includes a bone support B and does not materially deform duringbreathing. The soft palate SP is soft and is made up of mucous membrane,fibrous and muscle tissue extending rearward from the hard palate HP. Aleading end LE of the soft palate SP is anchored to the trailing end ofthe hard palate HP. A trailing end TE of the soft palate SP isunattached. Since the soft palate SP is not structurally supported bybone or hard cartilage, the soft palate SP droops down from the plane ofthe hard palate HP in an arcuate geometry of repose.

[0062] The pharyngeal airway passes air from the mouth M and the nasalpassages N into the trachea TR. The portion of the pharyngeal airwaydefined between opposing surfaces of the upper surface of the softpalate SP and the wall of the throat is the nasopharynx NP.

[0063] During normal breathing, the soft palate SP is in the relaxedstate shown in FIG. 1 with the nasopharynx NP unobstructed and with airfree to flow into the trachea TR from both the mouth M and the nostrilsN.

[0064] During swallowing, the soft palate SP flexes and extends (asshown in FIG. 2) to close the nasopharynx NP thereby preventing fluidflow from the mouth M to the nasal passages N. Simultaneously, theepiglottis EP closes the trachea TR so that food and drink pass onlyinto the esophagus ES and not the trachea TR. The soft palate SP is avalve to prevent regurgitation of food into the nose N. The soft palateSP also regulates airflow through the nose N while talking. Since thesoft palate SP performs such important functions, prior art techniquesfor surgically altering the soft palate SP can compromise thesefunctions.

[0065] The majority of snoring is caused by the soft palate SP flappingback and forth. If breathing is solely through the nose N with the mouthclosed, the trailing edge TE of the soft palate SP is sucked into thenasopharyngeal space NP obstructing the airway and subsequently fallsopening the airway in a repeating cycle. When the mouth is open, airflows over the upper and lower surfaces of the soft palate SP causingthe soft palate SP to flap up and down alternating in obstructing theoral and nasal passageways M, N. The snoring sound is generated byimpulses caused by rapid obstruction and opening of airways. Huang, etal., state the airway passage opening and closing occurs 50 times persecond during a snore. Huang, et al., utilize a spring-mass model (FIG.5) to illustrate oscillation of the soft palate in response to airflow(where the soft palate is the ball B of mass depending by a spring Sfrom a fixed anchor A).

[0066] Huang, et al., analogize the shortening of the soft palate SP inuvulopalatopharyngoplasty as effectively raising the critical air flowspeed at which soft palate flutter will occur. The shaded area SA inFIG. 3 shows the area of the trailing end TE of the soft palate SP to beremoved during this procedure. The alternative procedure proposed byHuang, et al., reduces the flexibility of the soft palate SP throughsurface scarring which is asserted as effecting the critical flow speed.The shaded area SA′ in FIG. 4 shows the area to be scarred by thisalternate procedure. In FIG. 4, dashed line L shows the demarcationbetween the soft and hard palates.

[0067] Using the spring-mass model of FIG. 5 as a convenient model ofthe soft palate SP, the present invention is directed to a surgicalimplant into the soft palate SP to alter the elements of the model andthereby alter the dynamic response of the soft palate SP to airflow. Theimplant can alter the mass of the model (the ball B of FIG. 5), thespring constant of the spring S, the dampening of the spring S or anycombination of these elements. Unlike the prior art surgical techniques,the implants that will be described are easy to insert in a smallincision resulting in reduced patient discomfort and are not exposed tothe interior of the mouth (such as the surface scarring of Huang, etal.) as a patient irritant. Also, as will be described, the degree ofdynamic remodeling can be fine tuned avoiding the need for excessiveanatomical modification and are reversible in the event of adverseconsequences.

[0068] FIGS. 6-7 illustrate a first embodiment of the present inventionwhere individual units 10 of mass (in the form of implantable modulardevices such as spheres or implants of other geometry) are imbedded inthe soft palate SP in close proximity to the trailing end TE. Withreference to the model of FIG. 5, the spheres add mass to themass-spring system thereby altering dynamic response to airflow andadding resistance to displacement and accelerating. The placement of theunits 10 of mass also alter the location of the soft palate's center ofmass further altering the model and dynamic response.

[0069] The embodiment of FIGS. 6-10 is tunable to a particular patientin that multiple modules 10 can be implanted (as illustrated in FIG. 7).This permits the surgeon to progressively increase the number ofimplanted modules 10 until the altered dynamic response is such thatsnoring inducing oscillation is abated at normal airflow. The individualmodules 10 may be placed into the soft palate SP through smallindividual incisions closed by sutures which is much less traumatic thanthe gross anatomical destruction of uvulopalatopharyngoplasty or thelarge surface area scarring proposed by Huang, et al.

[0070] Preferably, such modules 10 of mass are solid modules such asspheres of biocompatible material which are radiopaque (or radio-marked)and compatible with magnetic resonance imaging (MRI). Titanium is such amaterial. By way of non-limiting example, the modules 10 of mass may beabout 2-4 mm in diameter. In the case of pure, non-sintered titanium,each such sphere 10 would add 0.15-1.22 gm of mass to the trailing endTE of the soft palate SP and contribute to re-modeling the massdistribution of the soft palate SP. An example of an alternativematerial is any biocompatible ceramic.

[0071] As shown in FIG. 9, the spheres (labeled 10′ to distinguish fromthe version 10 of FIG. 8) may be sintered throughout or otherwiseprovided with tissue growth inducing material 12 on their outer surface.Such material may be a sintered outer layer or a coating or coveringsuch as a polyester fabric jacket. Such material permits and encouragestissue in-growth to secure the implant 10′ in place. Also, placement ofan implant 10 or 10′ will induce a fibrotic response acting to stiffenthe soft palate SP (and further alter the dynamic response andresistance to displacement and acceleration). A sintered or coatedsphere 10′ will enhance the fibrotic response and resulting stiffening.

[0072] While tissue in-growth and enhanced fibrotic response have thebenefits described above, such embodiments may make the implant 10′ moredifficult to remove in the event reversal of the procedure is desired.Therefore, as shown in FIG. 10 as an alternative, the spheres (labeled10″ to distinguish from the implants 10, 10′) may be coated with smoothcoating 14 (such as parylene or PTFE) to reduce fibrosis.

[0073] The embodiments of FIGS. 6-10 add to and relocate the mass of thespring-mass system of FIG. 5 to remodel the dynamic response. The amountof mass is selected to alter the dynamic response but not preclude thesoft palate SP being moved to close off nasal passages N duringswallowing. Through fibrotic response and incision healing, the spring Sof the model is stiffened.

[0074] In addition to modifying the mass profile of the spring-masssystem, the spring component S of FIG. 5 can be modified (alone or incombination with mass modification) to alter dynamic response. FIGS.11-16 illustrate an implant 20 in the form of a flexible strip forplacement in the soft palate. The use of the term “strip” herein is notintended to be limited to long, narrow implants but can also includeplates or other geometries implanted to alter the dynamic model of thesoft palate SP. Elongated strips are presently anticipated as apreferred geometry to facilitate ease of implant.

[0075] The strip 20 has a transverse dimension less than a longitudinaldimension. By way of non-limiting example, the strip may have a lengthL_(s) of about 20-30 mm, a thickness T_(s) of about 2-4 mm and a widthW_(s) of 5-10 mm. As shown in FIG. 11, the strip 20 is embedded in thesoft palate SP with the longitudinal dimension L_(s) extending fromadjacent the hard palate HP toward the trailing end TE of the softpalate SP. As shown in FIG. 12, multiple strips 20 may be embedded inthe soft palate SP extending either straight rearward or angled to thesides while extending rearward. The strips 20 may be formed straight(FIG. 14) or pre-shaped (FIG. 15) to have a rest shape approximate tothe side-cross section shape of the soft palate in a relaxed state.

[0076] The strips 20 may be any flexible, biocompatible material and arepreferably radiopaque or radio-marked as well as MRI compatible. Thestrips 20 need not be elastic and having a material spring constantbiasing them to their original shape. Such strips 20 could simply beflexible, plastically deformable strips which are stiffer than the softpalate SP to reinforce the soft palate SP and assist the soft palate SPin resisting deflection due to airflow. Such stiffening of the softpalate SP stiffens and dampens the spring S in the spring-mass system ofFIG. 5 and alters the dynamic response of the soft palate SP. The strip20 may be a spring having a spring constant to further resist deflectionof the soft palate SP as well as urging the soft palate SP to therelaxed state of FIG. 5. The stiffness of the strip 20, a springconstant of the strip 20, and the number of strips 20, are selected toavoid preclusion of closure of the soft palate SP during swallowing.Examples of suitable materials include titanium and nitinol (awell-known nickel-titanium alloy). As with the examples of FIGS. 9 and10, the strips 20 may be provided with tissue in-growth surfaces or maybe coated as desired. Also, the strips may be structurally modified tocontrol their flexibility. In FIG. 16, the bottom 22 of the strip 20(facing the tongue after placement) is provided with transverse notches24 to enhance downward flexion of the strip 20 relative to upwardflexion of the strip 20 following placement.

[0077]FIG. 17 provides an alternative to the strips 20 of FIG. 13. InFIG. 17, the strip 20′ includes a housing 26 having an interior space 28with an access opening 25. The interior space 28 extends in thelongitudinal dimension of the housing 26. The strip 20′ further includesa longitudinal insert 32 sized to be passed through the access opening25 and into the space 28. By way of non-limiting example, the housing 26could be silicone rubber (with radio-markers, not shown, to indicateplacement) and the inserts 32 could be titanium rods or other flexiblemember. With the embodiment of FIG. 17, the housing 26 (without aninsert) may be embedded in the soft palate SP. The housing 26 actsindependently as a stiffening strip to add stiffness to the soft palateSP to alter the soft palate's dynamic response. In the event furtherstiffening or a spring action is desired, the implant 20′ can beselectively tuned to the patient's unique dynamic model by placing theinsert 32 into the space 28 at the time of initial surgery or during asubsequent procedure. The embodiment of FIG. 17, permits selection of aninsert 32 from a wide variety of materials and construction so that aninsert 32 of desired characteristics (e.g., stiffness and spring action)can be selected to be inserted in the space 28 and alter the dynamicresponse as desired. The embodiment of FIG. 17 also permits laterremoval of the insert 32 and replacement with a different insert 32 ofdifferent properties for post-surgery modification of the soft palate'sdynamic response.

[0078] The embodiment of FIG. 18 is similar to that of FIG. 17. Thehousing 26′ is provided with multiple, parallel-aligned interior spaces28′ and access openings 25′. In addition to the function and benefits ofthe embodiment of FIG. 17, the number of inserts 32 may be varied toalter and adjust the dynamic response of the soft palate SP.

[0079]FIG. 19 illustrates a still further embodiment of the stripimplant. In FIG. 19, the strip 20′″ is a bladder having a housing 26″ inthe form of a completely sealed envelope of flexible synthetic materialdefining an interior space 28″. The envelope 26″ is preferablyself-sealing following needle injection. Fluid is injected into thehousing 26″ (e.g., through hypodermic needle 40 injection) to stiffenthe strip 20′″. Addition of fluid further stiffens the strip 20′″ andfurther alters the dynamic response of the soft palate SP. Removal offluid increases the flexibility. Unlike the embodiments of FIG. 17(where inserts 32 are most effectively replaced post-operatively throughincision to alter flexibility), the embodiment of FIG. 19 permitsselectively varying flexibility of the soft palate SP through needleinjection. An alternative to FIG. 19 is to fill the space 28″ with aso-called phase change polymer and inject a stiffening agent into thespace 28″ to alter the flexibility of the polymer.

[0080] FIGS. 20-23 illustrate a still further embodiment of the presentinvention. In the foregoing embodiments, the spring-mass system of FIG.5 is altered by altering the mass of the soft palate SP or the springcharacteristics of the soft palate SP. The dynamic response can also bealtered by altering the force acting on the spring-mass system. Namely,the force acting on the soft palate SP is generated by airflow over thesurface of the soft palate. The soft palate acts as an airfoil whichgenerates lift in response to such airflow. By modifying thelongitudinal (i.e., anterior to posterior) cross-sectional geometry ofthe soft palate SP, the aerodynamic response and, accordingly, thedynamic response are altered.

[0081] In the embodiments of FIGS. 20-23, the implant 30 is insertedinto the soft palate SP through an incision. The implant 30 has an ovalshape to cause deformation of the geometry of the soft palate SP. Priorto implantation, the implant 30 is preferably formed as a flat oval(FIGS. 20 and 22) for ease of insertion. After implantation, the implant30 expands to an enlarged oval (FIG. 21 and 23). While such expansioncould be accomplished mechanically (i.e., through balloon expansion),the implant 30 is preferably formed as a shape-memory alloy (such asnitinol) which expands to the enlarged shape in response to the warmthof the body. In addition to changing the aerodynamics of the soft palateSP, the implant 30 can be constructed with a mass and stiffness asdesired to alter the spring and mass components of the spring-masssystem of FIG. 5.

[0082] FIGS. 24-32 illustrate an expandable implant 50 and a deliverytool 60 for placing the implant 50 in the soft palate SP through a smallincision. In FIGS. 24 and 25, the implant 50 is best illustrated as aflexible rim 52 with a fibrosis-inducing agent in the form of a flexiblematerial, for example polyester fabric 54, retained on the rim 52. Therim 52 may be titanium or other material and resiliently biased to arest geometry shown as an oval in FIG. 24 having a fully expanded widthW and a length L. An oval is illustrated as a preferred geometry butother geometries may suffice. The geometries may include geometriesselected to alter the shape of the soft palate SP. The polyester fabric54 (such as Dacrong or the like) contains interstitial spaces forfibrosis and tissue integration to impart a stiffening to the softpalate SP.

[0083] The soft palate SP is schematically shown in FIGS. 29-32 with apalatal muscle PM extending distally from the bone B of the hard palateand surrounded by the soft tissue ST of the soft palate SP. The implant50 is placed by compressing the implant 50 against the bias of the rim52 into a compact cylindrical shape of length L and placing thecompressed implant 50 in a distal end of a cylindrical delivery tool 60.The distal tip 62 of tool 60 is a blunt beveled end to follow anincision and to separate tissue as the tip 62 is advanced. A rod 64 ispositioned proximal to the implant 50. The distal tip 62 comprises aseverable flap 68 such that pushing rod 64 urges the implant 50 out ofthe distal tip 62. When removed from the delivery tool 60, the implant50 springs back to an oval geometry.

[0084] The implant 50 is placed by forming a small incision 56 in thesoft palate. In FIG. 29, the incision is made on the lower surface ofthe soft palate. The procedure could also be performed through the uppersurface of the soft palate. The incision is sized to pass the distal tip62 of tool 60 which is substantially smaller than the full width W ofthe expanded implant 50.

[0085] Any suitable blunt dissecting tool may be inserted into incision56 to separate the soft tissue ST from the palatal muscle PM by anamount sufficient to receive the expanded implant 50. The distal tip 62is placed through the incision 56 and advanced through the soft palateSP with the distal tip 62 separating the soft tissue ST and the palatalmuscle PM (FIG. 30). The tool 60 can be advanced by the physiciantactilely noting position of the tool 60 or through any visualizationtechnique (e.g., an endoscope on the distal tip 62). When the distal tip62 is fully advanced, the outer tube 66 of tool 60 is retracted whileholding rod 64 in place causing the implant 50 to be expelled throughthe distal tip 62. After full expulsion of the implant 50, tool 60 isremoved through incision 56. The released implant 50 then expands intothe oval shape and residing between the palatal muscle PM and the softtissue ST (FIGS. 31 and 32).

[0086] In place, the fabric 54 of implant 50, encourages fibrosis andstiffening of the soft palate SP. By inserting a collapsed implant 50through a small incision 56, a large surface area of fibrosis (andgreater stiffening) can be achieved with a minimized incision 56(resulting in reduced patient discomfort). Also, while the implant 50 isillustrated as being resiliently expandable, the implant 50 could expandor swell in response to other factors such as shape memory alloys (e.g.,nitinol), smart polymers and balloon expandable and plasticallydeformable metals.

[0087] As an alternative to the foregoing, a catheter (not shown) can bepassed through incision 56 and passed through the soft palate SP. Thedelivery tool 60 can be passed through the catheter. If desired, acoring tool (not shown) can be passed through the catheter to removetissue from the soft palate SP prior to placing the implant 50 (or anyimplant of the previous embodiments). Also, for small implants, animplant can be placed through any short tube inserted into the softpalate through a needle poke and need not include a pre-incision.

[0088] With reference to FIGS. 33-36, a still further embodiment of theinvention is described. In FIGS. 33-36, an implant 80 is shown having acylindrical shape. The shape is illustrative only. The implant 80 may bedeployed through a delivery tool 60 as previously described.

[0089] The implant 80 includes two stiffening components. A firstcomponent 82 is a base of a bio-resorbable material such asbio-resorbable suture formed into a woven cylindrical shape. Suchmaterial has a stiffness greater than soft tissue and is absorbed intothe body over time. An example of such material is synthetic absorbablesuture such as polydioxanone suture sold by Ethicon, Inc. under thetrademark PDS II. Alternative materials could include absorbablebio-adhesives. A first component as described provides immediatepost-operative stiffening to reduce or eliminate snoring immediatelyfollowing placement of the implant 80 in the soft palate.

[0090] The second component 84 is any fibrosis inducing materialcombined with the first component 82. By way of non-limiting example,the second component may be filaments of polyester or polyester fabric(such as Dacron®) intertwined in the interstitial spaces of the firstcomponent 82. The presence of the second component 84 in the soft tissueof the soft palate SP induces fibrosis which stiffens the soft palate toreduce or eliminate snoring. The stiffening increases with timefollowing implantation until the fibrotic response is steady state. Thepolyester second component 84 is permanent and does not bio-resorb.Therefore, the fibrosis effect (and, hence, the snoring reducingstiffening) remains permanently following implantation and followingcomplete absorption of the first component 82.

[0091] The first component 82 and the second component 84 cooperate forthe implant 80 to provide effective stiffening immediatelypost-operatively and chronically thereafter. The first component has astiff material which stiffens the soft palate SP upon placement.However, over time, the first component is absorbed and the stiffeninginfluence reduces and is eliminated. The second component 84 is formedof very floppy material which does not materially stiffen the softpalate immediately upon implantation of implant 80. However, with time,fibrosis induced by the material of the second component 84 stiffens thesoft palate. This phenomena is illustrated in the graph of FIG. 36 inwhich the horizontal axis represents time and the vertical axisrepresents stiffening provided by the implant 80. Line A is stiffeningattributable to the first component 82 (which decays to zero as thefirst component is absorbed). Line B represents stiffening attributableto the second component (which is at near zero at implantation andincreases to a maximum representing a steady-state level of fibrosis).Line C represents stiffening of the soft palate SP which is a sum of thestiffening of lines A and B.

[0092] Therefore, with the embodiment of implant 80, immediatepost-operative stiffening (and snoring abatement) is achieved. Chronicstiffening is provided by fibrotic response which is permanent. Totalstiffening is controlled since the first component 82 is being absorbedas the fibrosis at the second component 84 increases.

[0093] FIGS. 37-39 show an alternative delivery system 100 for placingan implant in the soft palate SP. FIGS. 37-39 illustrate use of thenovel delivery system 100 with a cylindrical implant 102 (such asimplant 80 of FIG. 34). However, the method and apparatus described withreference to FIGS. 37-39 could also be used with other geometries (e.g.,the spherical implants of FIG. 7 or rectangular cross-section implantsof FIG. 13) as well as an expandable implant as such implant 50 of FIG.24.

[0094] A needle 66′ is provided having a ground beveled distal tip 61′for piercing tissue of the soft palate. The needle 66′ is hollow andcarries the implant 102 in sliding close tolerance. A rod 64′ isslidably positioned in the needle 66′ proximal to the implant 102. Asdescribed above with reference to FIGS. 26-32, the implant 102 iscarried by the needle 66′ to a desired implant site within the softpalate. At the desired site, the implant 102 is deployed by retractingthe needle 66′ while holding the rod 64′ in place. Relative movementbetween the rod 64′ and needle 66′ causes the rod 64′ to dispel theimplant 102 from the needle 66′ without need for moving the implant 102relative to the soft palate.

[0095] While advancing the needle 66′ through the soft palate, tissueand body fluids may be inclined to enter the needle 66′ and laterinterfere with discharge of the implant 102 from the needle 66′. Theembodiment of FIGS. 26-27 avoids such introduction of tissue and fluidsinto needle 60 by use of a flap 68 on the distal tip 62 of the needle66. The embodiment of FIGS. 38-39 provides an alternative technique toprevent admission of tissue into the needle 66′.

[0096] In FIGS. 38-39, the needle 66′ is provided with a plug 104 at thedistal tip 61′. Preferably, the plug 104 is a bio-resorbable material(such as the material of the first component 82 of the implant 80 ofFIG. 34.). After placing the plug 104 in the needle 66′ at the distaltip 61′, the distal tip 61′ may be ground to a final bevel resulting inthe plug 104 assuming the shape of the distal tip of 61′ as shown inFIGS. 38-39.

[0097] During discharge, the rod 64′ (due to retraction of the needle66′) urges both the plug 104 and implant 102 out of the needle 66′.Since the plug 104 is bio-resorbable, it resorbs into the patient's bodyover time. The implant 102 provides the therapeutic effect describedabove with reference to altering the dynamic response of the softpalate.

[0098] To avoid the plug 104 being urged proximally into the needle 66′,the needle 66′ includes a first bore 66 a′ having a diameter approximateto that of the rod 64′ and implant 102 and a second bore 66 b′ at thedistal tip 61′. The second bore 66 b′ is coaxial with the first bore 66a′ and is larger than the first bore 66 a′ so that an annular retainingedge 65′ is defined within the needle 66′. The plug 104 abuts theretaining edge 65′ and is restricted from being urged into the needle66′ as the needle 66′ is advanced through the tissue of the soft palate.

[0099] The needle 66′ may be porous at the distal tip 61′ so the needlewith a loaded implant 102 may be soaked for sterilization. FIGS. 43-44illustrate an implant in a perforated needle tip having through-holes69′ for perforations. No plug (such as plug 104) is shown in FIGS. 43-44to illustrate the needle 66′ can be used with or without a plug (inwhich case the needle 66′ has a constant diameter bore 67′). With theperforated needle, the implant 102 can be pre-loaded into the distal tipof the needle at time of assembly. This frees a physician from thecumbersome task of loading the implant into a needle. At or shortlybefore the implantation in the palate, the physician may soak the needledistal tip in a solution of antibiotic (such as well known antibioticsGentamycin or Betadine). The fluid antibiotic flows through perforations69′ in the needle and soaks the implant 102. As a result, a combinedneedle and implant can be fabricated economically with the combinationreadily treatable with antibiotic and with the needle disposablefollowing placement of the implant. During loading, the implant may besized larger than the needle bore 67′. Therefore, the implant expandsfollowing discharge.

[0100] FIGS. 40-41 illustrate an implant 102′ formed of twisted orbraided fibers 103 a, 103 b. While a single type fiber could be used,the embodiment is preferably formed of two different fibers 103 a, 103 bbraided or twisted together. One fiber 103 a may be provided forencouraging fibrotic response. Such a fiber 103 a may be polyester orsilk suture material (in which individual fibers 103 a may be formed ofbraided or twisted elements). The other fiber 103 b may be abio-resorbable fiber as in FIG. 33 (e.g., bio-resorbable suture materialwhich may include natural materials such as collagen or syntheticmaterials such as the PDS suture material previously described).Alternatively, the second fiber 103 b may be a non-resorbable materialsuch as polypropylene suture material to provide added stiffness to theimplant. The fibers 103 a, 103 b may be bonded together along the axiallength of the implant 102′ to provide added stiffness.

[0101] Referring to FIG. 42 and using implant 102 of FIG. 37 as anexample, a distal end 102 a of the implant 102 (i.e., the first end ofthe implant 102 to be discharged from needle 66′) may be scored orotherwise provided with an anchor 103 to flair outwardly followingdischarge from the needle 66′. Such flaring aids to anchor the implant102 in place while tissue in-growth matures. Such flaring can also beprovided by radially extending fibers on the implant 102 which arefolded down in the needle and which would radially project in the eventthe implant were to follow the needle 66′ during needle retraction.

[0102] A braiding operation as described with reference to FIGS. 40-41provides enhanced design flexibility. Such braiding can incorporate manydifferent types of fibers for various functions. For example,radio-opaque fibers may be provided in the braid to permit visualizationof the implant under fluoroscopy. The structure (and flexibility) of thebraided implant can be varied by adding a core material to the braid orvarying tightness of the braid. FIGS. 40 and 41 show a core or centralfiber 105. The central fiber 105 may be the same material as either offibers 103 a, 103 b or may be a different material to add stiffness orother mechanical property. For example, the fibers 103 a, 103 b may benon-bio-resorbable while core 105 is resorbable. Core 105 may be metalto add stiffness or be radio-opaque. Core 105 may be a coil orspring-shape core. In the construction of the braided implant 102′, allfibers 103 a, 103 b and core 105 are preferably co-terminus with theimplant 102′. In other words, the ends of the fibers 103 a, 103 b andcore 105 are positioned at the axial ends of the implant 102′. The endsmay be heat treated or otherwise adhered to prevent unraveling of thebraided implant 102′.

[0103]FIG. 45 illustrates an embodiment where the implant 102″ is acompliant implant to permit unimpeded stretching of the soft palate SP.Such a compliant implant may be a coil with a length aligned with theanterior-posterior axis of the soft palate SP. The implant 102″ iscompliant and stretches in response to tensile forces along its length.The implant 102″ may be a nitinol coil or may be any other materialformed in a compliant geometry (e.g., a coil). Such materials may be atissue growth-inducing material selected to induce tissue growth such asexpanded polytetraflouroethylene, polyester fabric or a woven materialor felt, or any other suitable material having a plurality of spaces foraccepting tissue growth.

[0104] FIGS. 46-49 illustrate embodiments of a contracting implant. InFIG. 46, the implant 102 ₁ includes a resilient coil 102 a ₁ with tissuegrowth inducing material 102 b, at its ends. By way of non-limitingexample, the coil 102 a ₁ may be nitinol and the tissue growth inducingmaterial 102 b ₁ be balls of polyester fabric. In an expanded state(FIG. 46), a bio-resorbable material 102 c ₁ (such as any of thosedescribed above) surrounds the coil 102 a ₁ and opposes the material 102b ₁. Since the length of the bio-resorbable material 102 c ₁ is greaterthan the length of the relaxed coil 102 a ₁, the coil 102 a ₁ isstretched for the implant 102 ₁ to have a length L₁. The implant 102 ₁in the expanded state is placed in the soft palate with the length L₁aligned with the anterior-posterior axis of the soft palate. Tissuegrows into the balls 102 b ₁ to attach to the balls 102 b ₁. Over time,the extension material 102 c ₁ resorbs. As a result, the implant 102 ₁contracts toward the relaxed length L₂ of FIG. 47. This urges the tissueof the soft palate to contract.

[0105] The embodiment of FIGS. 46-47 contracts in one dimension(length). The embodiment of FIGS. 48-49 contracts in three dimensions(length, width and thickness). In FIG. 48, the implant 102 ₂ is sown asa block of fibrous material (e.g., polyester fabric or a felt) havingfibers defining a plurality of interstitial spaces. Any bio-compatiblematerial having interior spaces which may be enlarged to expand thematerial against a resilient bias is suitable. The interstitial spacesare filled with a bio-resorbable material (such as those described aboveor a hydrogel). The filling of the spaces causes the spaces to expandagainst the natural resilient bias of the material for the implant 102 ₂to assume an expanded state having dimensions of length L, width W andthickness T.

[0106] The implant 102 ₂ in the expanded state is placed in the softpalate with the length L aligned with the anterior-posterior axis of thesoft palate. Tissue grows into the material of the implant 102 ₂. Overtime, the extension material within the interstitial spaces resorbs. Asa result, the implant 102 ₂ contracts toward the relaxed dimensions ofthe reduced length L′, width W′ and thickness T′ shown in FIG. 49. Thisurges the tissue of the soft palate to contract in three dimensions.

[0107] With all of the implants of FIGS. 45-49, the implant can have astiffness and dampening in response to flexing along its length to altera dynamic response of the soft palate to airflow. Also, the material ofthe implant can be selected for a fibrotic response of tissue of thesoft palate to stiffen the soft palate. By fabricating a soft or floppyimplant of high tissue-in-growth material, such fibrotic response can bethe dominant contributor to palatal stiffening (relative to the naturalstiffness of the implant material.

[0108] The foregoing describes numerous embodiments of an invention foran implant for the soft palate to alter a dynamic response of the softpalate. The invention is much less traumatic than prior surgicaltreatments. Further, the invention permits use of reversible proceduresas well as procedures which can be selectively tuned both during surgeryand post-operatively. Having described the invention, alternatives andembodiments may occur to one of skill in the art.

What is claimed is:
 1. A method for treating snoring of a patientattributable at least in part to motion of a soft palate of the patient,the method comprising: selecting an implant formed form material havinga longitudinal length and with said material being compliant in responseto tensile forces along said length, said material sized to be insertedinto said soft palate with said longitudinal length extending alignedwith an anterior-posterior axis of said soft palate and with a thicknessof said implant contained within a thickness of said soft palate;inserting said implant into said soft palate with said longitudinallength extending aligned with an anterior-posterior axis of said softpalate and with said thickness contained within said thickness of saidsoft palate.
 2. A method according to claim 1 wherein said implantincludes a portion formed of tissue growth-inducing material selected toinduce tissue growth.
 3. A method according to claim 2 wherein saidtissue growth-inducing material is expanded polytetraflouroethylene. 4.A method according to claim 2 wherein said tissue growth-inducingmaterial is polyester.
 5. A method according to claim 2 wherein saidtissue growth-inducing material is woven.
 6. An implant for treatingsnoring of a patient attributable at least in part to motion of a softpalate of the patient, the implant comprising: a bio-compatible materialhaving a longitudinal length between a proximal end and a distal end andhaving a thickness, said material being compliant in response to tensileforces along said length; said material sized to be inserted into saidsoft palate with said longitudinal length extending aligned with ananterior-posterior axis of said palate and with said thickness containedwithin a thickness of said soft palate.
 7. An implant according to claim6 including a tissue growth-inducing material having a plurality ofspaces for accepting tissue growth from said soft palate into saidspaces.
 8. An implant according to claim 7 wherein said tissuegrowth-inducing material is expanded polytetraflouroethylene.
 9. Animplant according to claim 7 wherein said tissue growth-inducingmaterial is polyester.
 10. An implant according to claim 7 wherein saidtissue growth-inducing material is woven.
 11. An implant according toclaim 6 wherein said tissue growth-inducing material is a coil.